A hierarchical CoFeS2/reduced graphene oxide composite for highly efficient counter electrodes in dye-sensitized solar cells
A hierarchical CoFeS2/reduced graphene oxide composite for highly efficient counter electrodes in dye-sensitized solar cells
复制标题
用于染料敏化太阳能电池高效对电极的分层 CoFeS2/还原氧化石墨烯复合材料
DOI：
10.1039/c7dt01511a
复制
发表时间：
2017
影响因子：
4
通讯作者：
Yu Xibin
中科院分区：
文献类型：
--
作者：
Zhang Minmin;Zai Jiantao;Liu Jie;Chen Ming;Wang Zeren;Li Guan;Qian Xuefeng;Qian Liwu;Yu Xibin
过渡金属硫化物具有良好的电催化能力和对I3−还原的稳定性，是DSSCs中高效稳定的CE材料的潜在候选者。然而，硫化物的低电导率不利于电子的收集和转移过程，需要优化I−/I3−的吸收/解吸和扩散过程，以实现对Pt的高电催化活性。本文通过原位转化CoFeS2/还原氧化石墨烯（CoFeS2/rGO）复合材料，将CoFe层锚定在rGO上。由于Co和Fe的协同作用、纳米片形成的独特的三维层次结构以及rGO的导电性，CoFeS2/rGO ce对I3−还原为I−表现出了良好的电催化活性和稳定性，并且DSSCs的效率高达8.82%，高于基于Pt（8.40%）和纯CoFeS2 (8.30%) ce的器件。此外，该装置还具有活动启动快、稳定性好、多次启动/停止能力高等特点。结果表明，所制备的CoFeS2/rGO复合材料有望成为DSSCs中Pt的替代材料。
Transition metal sulfides are a kind of potential candidates for efficient and stable CE materials in DSSCs due to their good electrocatalytic ability and stability towards I3− reduction. However, the low conductivity of sulfides is harmful for the electron collection and transfer process, and the absorption/desorption and diffusion process of I−/I3− should be optimized to achieve high electrocatalytic activity over Pt. Herein, a hierarchical CoFeS2/reduced graphene oxide (CoFeS2/rGO) composite was rationally designed and prepared via the in situ conversion of CoFe layer double hydroxide anchored on rGO. Due to the synergistic effects of Co and Fe, unique 3D hierarchical structures formed by nanosheets, and the conductivity of rGO, the CoFeS2/rGO CEs exhibited good electrocatalytic activity and stability towards the reduction of I3− to I−, and the DSSCs could also achieve a high efficiency of 8.82%, higher than those of the devices based on Pt (8.40%) and pure CoFeS2 (8.30%) CEs. Moreover, the devices also showed the characteristics of fast activity onset, good stability, and high multiple start/stop capability. The results indicated that the developed CoFeS2/rGO composite could be a promising alternative for Pt in DSSCs.